Method for production of an object and object produced by said method

ABSTRACT

The object ( 10, 10 ′) comprises a first layer ( 1 ), for example with a back injection of a second layer ( 2 ), whereby the first layer is plastically deformable and comprises a front face ( 1   a ) and a rear face ( 1   b ). The back injection of the first layer ( 1 ) takes place in an injection mould. Before the back injection, the first layer ( 1 ) is partly provided with a coating ( 4 ′) on the front face ( 1   a ) thereof and said coating is hardened. The first layer ( 1 ) is then placed in an injection mould ( 6 ). The first layer ( 1 ) is then back injected in the injection mould ( 6 ), thus forming the second layer ( 2 ), such that the first layer ( 1 ) is pressed with the front face ( 1   a ) thereof on an inner side ( 7 ) of the injection mould ( 6 ) and the hardened coating ( 4 ′) on the first layer ( 1 ) is deformed and at least partly pressed into the first layer ( 1 ). The coating ( 4 ′) is preferably applied by printing, for example by means of a screen printing method. The method permits the production of back-injected films with a front face ( 1   a ) which is structured or at least appears to be.

The invention relates to a method for production of an object with afirst layer, which is bonded to a second layer, the first layer beingplastically deformable and having a front side and a rear side, and thebonding of the two layers taking place in an injection mold.

In-mold lamination of films by the injection-molding process has longbeen known in the prior art. This involves inserting a film, for examplea metal foil, into an injection mold and injecting thermoplasticmaterial behind it. It is also known to provide the front side of thefilm with depressions, these depressions forming for example aninscription or a pattern. For this purpose, the injection mold isstructured on the inside in a way corresponding to the depressions to beproduced on the film. During the in-mold lamination, the film is pressedagainst the structured inner side of the injection mold. Such a processis known for example for the production of inserts in sill trimmoldings. These inserts are consequently respectively provided on theirfront side with depressions which give an optical effect of depth. Thedepressions form an inscription for example. This method makes itpossible for such objects to be mass produced comparativelyinexpensively.

The invention is based on the object of providing a method of the statedtype which offers further possibilities for the design of the objectsand which is nevertheless suitable for automated mass production. It isconsequently intended to be possible with the method that the front sideof the object can be designed with the greatest possible diversity andin an esthetically attractive manner.

In the case of the method according to the invention, the first layer ispartially provided with a coating on its front side. This coating issubsequently cured. The first layer with the cured coating is introducedinto an injection mold. In this injection mold, plastic is for exampleinjected behind the first layer, this layer being pressed with its frontside against an inner side of the injection mold. The cured coatingthereby changes the form of the first layer and creates an impression init. The pressing of the coating into the first layer preferably takesplace in such a way that a depression is formed in it. The laminatedlayer is finally demolded. The choice of the coating allows a front sidewhich is textured to be produced and/or for example the choice of acolored coating allows it to be made of any color desired.

The coating is preferably pressed completely into the first layer. If,according to a development of the invention, the coating is producedfrom a transparent ink, a special optical effect is obtained. Inparticular, this allows a particularly interesting effect of depth to beachieved. As a result, the flanks of the depressions become visible.

According to a development of the invention, the coating is produced bya printing ink. This preferably takes place by means of screen printingor pad printing. This allows different patterns or inscriptions to beapplied in a simple way. The curing of the printing ink preferably takesplace thermally, by UV radiation or by exposure to air. Curing by achemical reaction, or by a combination of various processes, is alsoconceivable.

According to a development of the invention, the first layer is analuminum foil or steel foil. Foils made for example of copper, brass orother suitable metals are also conceivable, however. During the in-moldlamination, these foils are deformed by the cured coating and, in thecase of the injection-molding, are substantially impressed by thecoating. As a result, very exact patterns and inscriptions which cangive a special optical effect can be produced. The surface can in factbe made multicolored as desired. What is important is that the statedmethod steps can be automated. The method is consequently also suitablefor mass production with large numbers of items.

The invention also relates to an object produced by the stated method.The object is characterized in that the front side of the first layerpartially has depressions which are deformations of a coating. Thecoating is preferably a printing ink. This is preferably arranged suchthat it is recessed in the first layer. According to a development ofthe invention, the coating is a semi-transparent or transparent printingink. This allows a particularly interesting effect of depth to beachieved.

According to a preferred configuration, the object is a decorative part,in particular a trim molding for a motor vehicle. Such trim can beproduced by the method according to the invention particularlyinexpensively and in large numbers of items. Nevertheless, the sill trimmolding is durable and, as mentioned above, can be formed with a specialfront side.

Further advantageous features emerge from the dependent patent claims,the description which follows and the drawing.

Exemplary embodiments of the invention are explained in more detailbelow on the basis of the drawing, in which:

FIG. 1 shows a section through part of an object according to theinvention,

FIG. 2 shows a view of an object according to the invention,

FIG. 3 shows a section through a portion of an object according to theinvention according to one variant, and

FIGS. 4 to 7 schematically show individual steps of the method accordingto the invention.

FIGS. 1 and 2 show a sill trim molding 10, which has a first layer 1with a front side 1 a and a rear side 1 b and also a laminated-on secondlayer 2. The first layer 1 is preferably an aluminum foil or steel foil.The foil 1 may, however, also be made of some other suitable plasticallydeformable material, in particular metal. The layer 1 may also be acomposite of more than one layer, for example a metal layer and avarnish layer. For example, the foil 1 may also be made of copper orbrass. The thickness D of the first layer 1 is preferably less thanapproximately 0.5 mm. The thickness preferably lies in the range from0.1 to 0.3 mm. The second layer consists of a plastic, in particular athermoplastic, which is laminated onto the rear side 1 b of the firstlayer 1 by the injection-molding process. For better adhesion of thesecond layer 2, on the rear side 1 b is provided with an adhesionpromoter 8 known per se before the in-mold lamination.

According to FIG. 2, a representation B, which is for example aninscription or any desired pattern, is visible on the front side 1 a.The representation B only extends over a partial region of the frontside 1 a. It is formed by a coating 4, which is arranged in a depression3 of the first layer 1. As FIG. 1 shows, an upper side 4 a of thecoating 4 is in the plane of the front side 1 a. This is not absolutelynecessary, however, as the exemplary embodiment 10′ according to FIG. 3shows. In the case of this embodiment, a coating 14 has an upper side 14a, which is located below the front side 1 a′ of a first layer 1′. Inprinciple, the upper side 14 a could also be arranged above the frontside 1 a′. Moreover, it is conceivable in principle for the coating 4 or14 to comprise more than one layer.

The method for production of an object 10 is explained in more detail onthe basis of FIGS. 4 to 7.

Firstly, a first layer 1, for example an aluminum foil, is cut into theintended shape, which however is not absolutely necessary, and ispartially provided on its front side 1 a with a coating 4′ of thethickness H. The coating 4′ is applied for example by printing with aprinting ink. The printing may also be multicolored. This may take placefor example by screen printing or pad printing. The coating 41 may infact be any desired representation B, for example an inscription or apattern, as is represented for example in FIG. 2. The height H of thecoating 4′ above the upper side 1 a lies in the range from 2 to 1000micrometers, preferably in the range from 2 to 100 micrometers. Aparticularly preferred height H is approximately 4 to 10 micrometers.

After the coating 4′ is applied, it is cured. This may take place forexample thermally, with UV radiation or by exposure to air. The curingtakes place for example at approximately 100° C., this temperature ofcourse being dependent on the type of coating 4′.

After the curing, the first layer 1 is inserted into the injection mold6. This preferably takes place automatically in a way known per se. Theinjection mold 6 has an inner side 7, which is preferably planar orconvex and on which the first layer 1 is to be placed with its frontside 1 a. After closing of the injection mold 6, a layer 2 is laminatedbehind the first layer 1. In order to improve the adhesion of thein-mold laminated second layer 2, an adhesion promoter 8 is preferablyapplied to the rear side 1 b of the first layer 1 according to FIG. 5.Adhesion promoters 8, which improve the adhesion of plastic on metal,for example aluminum, are known per se to a person skilled in the art.While the plastic is being injected behind the first layer 1, the latteris pressed with its front side 1 a against the inner side 7 of theinjection mold 6 with comparatively high pressure and within a veryshort time interval. The pressure is, for example, 600 bar. When thefirst layer is pressed against the inner side 7, the coating 4′ forms animpression in the first layer 1. The impressing or deforming of thefirst layer 1 causes corresponding depressions 3, which are formed in away corresponding to the coating 4′, to be created in the first layer 1.Tests have surprisingly shown that the depressions 3 are comparativelysharp-edged; the depressions 3 consequently correspond to the coating4′. After the in-mold lamination with a coating 4, the depressions 3 arefilled, which however is not absolutely necessary. During thepressing-in, the coating 4′ is deformed only insignificantly. The layer1 is made to project on its rear side, as can be seen for example inFIG. 1.

After the in-mold lamination, cooling and deforming are performed in away known per se. The object 10 shown in FIG. 7 is then obtained. Thiscomprises a composite of the first layer 1 and the second layer 2, whichare firmly bonded to each other. The upper side 1 a is provided with animage or some other representation, which is formed by the coating 4pressed into the first layer 1. In the case of this exemplaryembodiment, the outer side 4 a is flush with the front side 14 a. Aprotective layer, for example a varnish, may be applied to the frontside 1 a, and may also cover the front side 4 a of the coating 4. Thefront side 14 a may, however, also be protruding or recessed, as FIG. 3shows. In order to produce the object according to FIG. 3, the coating14 is formed with more than one layer. An outer layer is removed afterthe in-mold lamination, for example dissolved by means of a solvent. Inprinciple, the entire coating 4 or 14 may also be removed, in particulardissolved from the depression 3 or 3′. In this case, the front side 1 aor 1 a′ is textured with depressions 3 and 3′, respectively. Aconfiguration in which some of the depressions are empty and some othersare filled with a coating 4 or 14 is also conceivable.

The coating 4 or 14 may be transparent or translucent, semi-transparentor opaque. A front side 1 a or 1 a′ which visually appears as a texturedsurface with an effect of depth is obtained in this way. Since thecoating 4 or 4′ may be multicolored, there are numerous possibilitiesfor the design of the front side 1 a. Since the printing of an upperside and the in-mold lamination by the injection-molding process areinexpensive and can be automated, mass production of large numbers ofitems is also possible.

The object 10 is, in particular, a decorative part, in particular a trimmolding for a passenger vehicle. The object 10 or 10′ may, however, alsobe some other article, for example a covering plate, a door plate, ahousing of a device, for example of a sanitary fitting, a connectingpart, a covering strip, etc. The object 10 or 10′ is generallytwo-dimensional, but this is not absolutely necessary.

1. A method for production of an object (10, 10′) with a first layer(1), which is bonded to a second layer (2), the first layer beingplastically deformable and having a front side (1 a) and a rear side (1b), and the bonding of the two first layer (1, 2) taking place in aninjection mold, characterized by the following method steps: a) thefirst layer (1) is partially provided with a coating (4′) on its frontside (1 a), b) the coating (4′) is cured, c) the first layer (1) isinserted into an injection mold (6), d) the first layer (1) is pressedwith its front side (1 a) against an inner side (7) of the injectionmold (6), the cured coating (4′) changing the form of the first layer(1) and at least partially creating an impression in the first layer(1), e) the product (10, id) is demolded.
 2. The method as claimed inclaim 1, characterized in that the coating (4′) is impressedsubstantially completely into the first layer (1) and forms one or moredepressions (3) in the latter (4′).
 3. The method as claimed in claim 1or 2, characterized in that the first layer (1) is laminated in theinjection mold (6) by injecting plastic behind it and the second layer(2) is thereby formed.
 4. The method as claimed in one of claims 1 to 3,characterized in that a thermoplastic is injected behind the first layer(1).
 5. The method as claimed in one of claims 1 to 4, characterized inthat the first layer (1) is provided with an adhesion promoter (8) onits rear side (1 b) before the in-mold lamination.
 6. The method asclaimed in one of claims 1 to 5, characterized in that the first layer(1) is a metal foil, in particular an aluminum foil or steel foil. 7.The method as claimed in one of claims 1 to 7, characterized in that thethickness (D) of the first layer (1) is 0.5 mm or less, preferably 0.1mm or less.
 8. The method as claimed in one of claims 1 to 6,characterized in that the thickness (D) of the first layer (1) is 0.1 to0.3 mm.
 9. The method as claimed in one of claims 1 to 8, characterizedin that the coating (4′) has a thickness (H) of from 2 to 1000micrometers, preferably 2 to 100 micrometers.
 10. The method as claimedin one of claims 1 to 9, characterized in that the thickness (H) of thecoating (4′) is 4 to 10 micrometers.
 11. The method as claimed in one ofclaims 1 to 10, characterized in that the coating (4′) is an imprint.12. The method as claimed in one of claims 1 to 11, characterized inthat the coating (4′) is produced from one or more printing inks. 13.The method as claimed in claim 12, characterized in that the printingink is at least partially translucent, transparent or semi-transparent.14. The method as claimed in one of claims 1 to 13, characterized inthat the coating (4′) is applied by screen printing or pad printing. 15.The method as claimed in one of claims 1 to 14, characterized in thatthe coating (4′) is cured thermally, with UV radiation, chemically or byexposure to air.
 16. The method as claimed in claim 15, characterized inthat the imprint (4′) is cured at 70 to 100° C., preferablyapproximately
 800. 17. The method as claimed in one of claims 1 to 16,characterized in that the coating (4′) comprises more than one layer.18. The method as claimed in one of claims 1 to 18, characterized inthat the coating (4) is at least partially removed, preferably dissolvedaway or pulled off.
 19. The method as claimed in one of claims 1 to 18,characterized in that a decorative part or a trim molding for a motorvehicle is produced.
 20. An object, produced by the method as claimed inclaim 1, characterized in that the front side (1 a) of the first layer(1) partially has a depression or depressions (3), which aredeformations and in particular impressions created by a partial coating(4).
 21. The object as claimed in claim 20, characterized in that thedepression or depressions (3) are completely or partially filled with aprinting ink.
 22. The object as claimed in claim 20 or 21, characterizedin that the coating (4) has an upper side (4 a) which is arranged deeperthan the front side (1 a) of the first layer (1).
 23. The object asclaimed in one of claims 20 to 22, characterized in that the coating (4)is transparent or opaque.
 24. The object as claimed in one of claims 20to 23, characterized in that the coating (4) is a printing ink.
 25. Theobject as claimed in one of claims 20 to 24, characterized in that thefirst layer (1) is a metal foil and has a thickness (D) which is lessthan 0.5 mm, preferably 0.1 to 0.3 mm.
 26. The object as claimed in oneof claims 20 to 25, characterized in that it is a decorative part or atrim molding for a motor vehicle.
 27. The object as claimed in one ofclaims 20 to 26, characterized in that the second layer (2) is aninjection-molded part.